X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=sched.c;h=144eaf6e21a670d1243a07d00689cf6a3fbd1900;hp=6b893d33c9ccb2b07c65fcb8fd02ac168d7bc6f8;hb=245b44acd4f1c16395844683f6aff10699967dc0;hpb=c075e867311c77dfb7171241597e613290d1f62b diff --git a/sched.c b/sched.c index 6b893d33..144eaf6e 100644 --- a/sched.c +++ b/sched.c @@ -1,19 +1,7 @@ /* - * Copyright (C) 2006 Andre Noll + * Copyright (C) 2006-2007 Andre Noll * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + * Licensed under the GPL v2. For licencing details see COPYING. */ /** \file sched.c paraslash's scheduling functions */ @@ -27,16 +15,10 @@ #include "string.h" #include "error.h" -/** - * The scheduler manages two lists of tasks. The pre_select list contains - * pointers to functions that are called before calling select() from the main - * loop. Similarly, \a post_select_list is a list of function pointers each of - * which is called after the select call. - */ -struct list_head pre_select_list, post_select_list; +static struct list_head pre_select_list, post_select_list; +static int initialized; static struct timeval now_struct; - struct timeval *now = &now_struct; static void sched_preselect(struct sched *s) @@ -71,7 +53,9 @@ static void sched_post_select(struct sched *s) /** * the core function for all paraslash programs * - * Short and sweet. It updates the global \a now pointer, calls all registered + * \param s pointer to the scheduler struct + * + * This function updates the global \a now pointer, calls all registered * pre_select hooks which may set the timeout and add any file descriptors to * the fd sets of \a s. Next, it calls para_select() and makes the result available * to the registered tasks by calling their post_select hook. @@ -83,7 +67,8 @@ static void sched_post_select(struct sched *s) */ int sched(struct sched *s) { - + if (!initialized) + return -E_NOT_INITIALIZED; gettimeofday(now, NULL); again: FD_ZERO(&s->rfds); @@ -102,6 +87,17 @@ again: goto again; } +/** + * initialize the paraslash scheduler + */ +static void init_sched(void) +{ + PARA_INFO_LOG("%s", "initializing scheduler\n"); + INIT_LIST_HEAD(&pre_select_list); + INIT_LIST_HEAD(&post_select_list); + initialized = 1; +}; + /** * add a task to the scheduler * @@ -114,14 +110,16 @@ again: */ void register_task(struct task *t) { + if (!initialized) + init_sched(); PARA_INFO_LOG("registering %s (%p)\n", t->status, t); if (t->pre_select) { PARA_DEBUG_LOG("pre_select: %p\n", &t->pre_select); - list_add(&t->pre_select_node, &pre_select_list); + para_list_add(&t->pre_select_node, &pre_select_list); } if (t->post_select) { PARA_DEBUG_LOG("post_select: %p\n", &t->pre_select); - list_add(&t->post_select_node, &post_select_list); + para_list_add(&t->post_select_node, &post_select_list); } } @@ -135,6 +133,8 @@ void register_task(struct task *t) */ void unregister_task(struct task *t) { + if (!initialized) + return; PARA_INFO_LOG("unregistering %s (%p)\n", t->status, t); if (t->pre_select) list_del(&t->pre_select_node); @@ -142,15 +142,6 @@ void unregister_task(struct task *t) list_del(&t->post_select_node); }; -/** - * initialize the paraslash scheduler - */ -void init_sched(void) -{ - INIT_LIST_HEAD(&pre_select_list); - INIT_LIST_HEAD(&post_select_list); -}; - /** * unregister all tasks * @@ -161,11 +152,14 @@ void sched_shutdown(void) { struct task *t, *tmp; + if (!initialized) + return; list_for_each_entry_safe(t, tmp, &pre_select_list, pre_select_node) unregister_task(t); /* remove tasks which do not have a pre_select hook */ list_for_each_entry_safe(t, tmp, &post_select_list, post_select_node) unregister_task(t); + initialized = 0; }; /** @@ -181,6 +175,9 @@ char *get_task_list(void) { struct task *t, *tmp; char *msg = NULL; + + if (!initialized) + return NULL; list_for_each_entry_safe(t, tmp, &pre_select_list, pre_select_node) { char *tmp_msg; tmp_msg = make_message("%s%p\tpre\t%s\n", msg? msg : "", t, t->status); @@ -207,13 +204,16 @@ char *get_task_list(void) * Find the task identified by \a id, set the tasks' return value to * \p -E_TASK_KILLED and call the event handler of the task. * - * \return Positive on sucess, negative if \a id does not correspond to a - * registered task. + * \return Positive on success, negative on errors (e.g. if \a id does not + * correspond to a registered task). */ int kill_task(char *id) { struct task *t, *tmp; char buf[20]; + + if (!initialized) + return -E_NOT_INITIALIZED; list_for_each_entry_safe(t, tmp, &pre_select_list, pre_select_node) { sprintf(buf, "%p", t); if (strcmp(id, buf))